FIG. 15 is an exploded view of prior art wedge clutch 210. Clutch 210 includes carrier 212, clutch plates 214, wedge clutch plates 216, hub 218, pins 220, plate 222 and plate 224. Pins 220 pass through openings 226 in plates 214 and 216 and are connected to plates 222 and 224 via openings 228 and 230, respectively. Pins 220 include portions 220A and portions 220B. The outside diameter of portions 220A is less than the outside diameter of portion 220B. Plates 214 are non-rotatably connected to carrier 212 via protrusions 232 in slots 234 in carrier 212. Plates 222 and 224 are non-rotatably connected to hub 218. Plates 216 include ramps 236 extending radially inward along circumferential direction CD1. Hub 2186 include ramps 238 extending radially outward in circumferential direction CD2 opposite direction CD1.
For a first synchronization stage, a first actuator (not shown) displaces pins 220 such that portions 220B are disposed in openings 226. The outer diameter of portions 220B is such that portions 220B essentially fill openings 226 and prevent rotation of plates 216 with respect to hub 218. A second actuator (not shown) clamps plates 214 and 216 such that torque received by hub 218, for example, is transmitted to carrier 212 via plates 214 and 216.
For a second synchronization stage, the first actuator displaces the pins such that portions 220A are disposed in openings 226 and the second actuator is de-activated to enable rotation between plates 216 and hub 218. Due to the smaller outer diameter of portions 220A: pins 220 are able to rotate in openings 226; plates 216 and hub 218 are able to rotate with respect to each other; and ramps 236 and 238 slide along each other to displace plates 216 radially outward. The radially outward displacement of plates 216 non-rotatably connects carrier 212 and hub 218.
The use of two actuators increases the cost, complexity, size, and energy requirements of clutch 210 and reduces the robustness and reliability of clutch 210.